org.tentackle.sql.backends.Informix Maven / Gradle / Ivy
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/*
* Tentackle - https://tentackle.org
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package org.tentackle.sql.backends;
import org.tentackle.common.Service;
import org.tentackle.sql.Backend;
import org.tentackle.sql.BackendException;
import org.tentackle.sql.BackendPreparedStatement;
import org.tentackle.sql.NonStandardCommons;
import org.tentackle.sql.SqlNameType;
import org.tentackle.sql.SqlType;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Types;
/**
* Backend for Informix.
*
* @author harald
*/
@Service(Backend.class)
public class Informix extends AbstractSql92Backend {
// maximum length for identifiers, names, etc...
private static final int MAX_NAME_LENGTH = 128;
/** NVL keyword. */
public static final String SQL_NVL = "NVL"; // instead of COALESCE
/** FIRST string. */
public static final String SQL_FIRST = "FIRST ";
/** SKIP string. */
public static final String SQL_SKIP = "SKIP ";
/** FIRST string. */
public static final String SQL_FIRST_PAR = SQL_FIRST + "? ";
/** SKIP string. */
public static final String SQL_SKIP_PAR = SQL_SKIP + "? ";
/**
* Creates the Informix backend.
*/
public Informix() {
// see -Xlint:missing-explicit-ctor since Java 16
}
@Override
public int getMaxNameLength(SqlNameType nameType) {
return MAX_NAME_LENGTH;
}
@Override
public boolean isMatchingUrl(String url) {
return url.contains(":informix");
}
@Override
public String getName() {
return "Informix";
}
@Override
public String getDriverClassName() {
return "com.informix.jdbc.IfxDriver";
}
@Override
public String getBackendId(Connection connection) {
// @todo
return null;
}
@Override
public Connection createConnection(String url, String username, char[] password)
throws SQLException {
return DriverManager.getConnection (
url +
";user=" + username +
";password=" + createPassword(password));
}
@Override
public String getCoalesceKeyword() {
return SQL_NVL;
}
@Override
public void buildSelectSql(StringBuilder sqlBuilder, boolean writeLock, int limit, int offset) {
boolean insertSelect = isLeadingSelectMissing(sqlBuilder);
if (limit > 0) {
sqlBuilder.insert(0, SQL_FIRST_PAR);
}
if (offset > 0) {
sqlBuilder.insert(0, SQL_SKIP_PAR); // SKIP comes before FIRST
}
if (insertSelect) {
sqlBuilder.insert(0, SQL_SELECT);
}
if (writeLock) {
sqlBuilder.append(SQL_FOR_UPDATE);
}
}
@Override
public int setLeadingSelectParameters(BackendPreparedStatement stmt, int limit, int offset) {
int index = 1;
if (offset > 0) {
stmt.setInt(index++, offset);
}
if (limit > 0) {
stmt.setInt(index++, limit);
}
return index;
}
@Override
public int setTrailingSelectParameters(BackendPreparedStatement stmt, int index, int limit, int offset) {
return index;
}
@Override
public int getMaxSize(SqlType sqlType) {
return switch (sqlType) {
case DECIMAL -> 31;
case VARCHAR -> 255;
default -> super.getMaxSize(sqlType);
};
}
@Override
public String sqlTypeToString(SqlType sqlType, int size) {
return switch (sqlType) {
case BIT -> TYPE_BOOLEAN;
case TINYINT, SMALLINT -> TYPE_SMALLINT;
case INTEGER -> TYPE_INT;
case BIGINT -> TYPE_INT8;
case FLOAT -> TYPE_SMALLFLOAT;
case DOUBLE -> TYPE_FLOAT;
case DECIMAL -> TYPE_NUMBER;
case CHAR -> TYPE_CHAR_1;
case VARCHAR -> TYPE_VARCHAR;
case DATE -> TYPE_DATE;
case TIME -> TYPE_DATETIME;
case TIMESTAMP -> TYPE_DATETIME_YEAR_TO_SECOND;
case BLOB -> TYPE_BYTE;
case CLOB -> TYPE_CLOB;
default -> super.sqlTypeToString(sqlType, size);
};
}
@Override
public SqlType[] jdbcTypeToSqlType(int jdbcType, int size, int scale) {
return switch (jdbcType) {
case Types.SMALLINT, Types.TINYINT -> new SqlType[]{SqlType.TINYINT, SqlType.SMALLINT};
case Types.TIMESTAMP, Types.TIME -> new SqlType[]{SqlType.TIME, SqlType.TIMESTAMP};
default -> super.jdbcTypeToSqlType(jdbcType, size, scale);
};
}
@Override
public boolean isSequenceSupported() {
return true;
}
@Override
public boolean isSchemaSupported() {
// there is a CREATE SCHEMA, but this is a different beast
return false;
}
@Override
public String sqlCreateSequence(String name, Long start, Long increment) {
return NonStandardCommons.sqlCreateSequence(name, start, increment);
}
@Override
public String sqlNextFromSequence(String name) {
return "SELECT " + name + ".NEXTVAL";
}
@Override
public String sqlRenameColumn(String tableName, String oldColumnName, String newColumnName) {
return "RENAME COLUMN " + tableName +
"." +
oldColumnName +
" TO " +
newColumnName +
";\n";
}
@Override
public String sqlRenameIndex(String tableName, String oldIndexName, String newIndexName) {
return "RENAME INDEX " + oldIndexName +
" TO " +
newIndexName +
";\n";
}
@Override
public String sqlAddColumn(String tableName, String columnName, String comment, SqlType sqlType, int size, int scale,
boolean nullable, Object defaultValue) {
return SQL_ALTER_TABLE + tableName +
" ADD (" +
sqlCreateTableAttributeWithoutComment(columnName, sqlType, size, scale, nullable, defaultValue, false, false) +
");\n";
}
@Override
public String sqlDropColumn(String tableName, String columnName) {
return SQL_ALTER_TABLE + tableName +
" DROP (" +
columnName +
");\n";
}
@Override
public String sqlAlterColumnType(String tableName, String columnName, String comment, SqlType sqlType,
int size, int scale, boolean nullable, Object defaultValue) {
return SQL_ALTER_TABLE + tableName +
" MODIFY (" +
sqlCreateTableAttributeWithoutComment(columnName, sqlType, size, scale, nullable, defaultValue, false, false) +
");\n";
}
@Override
public String sqlAlterColumnDefault(String tableName, String columnName, SqlType sqlType, Object defaultValue) {
StringBuilder buf = new StringBuilder(SQL_ALTER_TABLE);
buf.append(tableName);
buf.append(" MODIFY (");
buf.append(columnName);
buf.append(" ");
if (defaultValue == null) {
buf.append("DROP DEFAULT");
}
else {
buf.append("SET DEFAULT ");
buf.append(valueToLiteral(sqlType, defaultValue));
}
buf.append(");\n");
return buf.toString();
}
@Override
protected String extractWhereClause(String sql, int whereOffset) {
int ndx = sql.indexOf(SQL_FIRST);
if (ndx >= 0) {
throw new BackendException("backend does not support merging selects with FIRST");
}
ndx = sql.indexOf(SQL_SKIP);
if (ndx >= 0) {
throw new BackendException("backend does not support merging selects with SKIP");
}
return super.extractWhereClause(sql, whereOffset);
}
@Override
protected boolean isDropIfExistsSupported() {
return true;
}
}